What is the theme in Man and Superman by George Bernard Shaw?

Sex is the main theme of this story. Man and Superman expounds Shaw's pointed view of humanity's sexual nature. In this play, Ann Whitefield woos her newly appointed guardian, John Tanner, and he, in spite of his anti-romantic persona, falls for her. He does not love her in the conventional sense, but falls prey to the "Life Force" that she exudes. It is more a matter of sexual attraction than it is of romanic love. Shaw's idea of this Life Force derives from French philosopher Henri Bergson's Olan vital, or spirit of life.